/* zmalloc - total amount of allocated memory aware version of malloc()
 *
 * Copyright (c) 2009-2010, Salvatore Sanfilippo <antirez at gmail dot com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of Redis nor the names of its contributors may be used
 *     to endorse or promote products derived from this software without
 *     specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>

/* This function provide us access to the original libc free(). This is useful
 * for instance to free results obtained by backtrace_symbols(). We need
 * to define this function before including zmalloc.h that may shadow the
 * free implementation if we use jemalloc or another non standard allocator. */
void zlibc_free ( void *ptr )
{
    free (ptr);
}

#include <string.h>
#include <pthread.h>
#include "../lib/zmalloc.h"

#ifdef HAVE_MALLOC_SIZE
#define PREFIX_SIZE (0)
#else
#if defined(__sun) || defined(__sparc) || defined(__sparc__)
#define PREFIX_SIZE (sizeof(long long))
#else
#define PREFIX_SIZE (sizeof(size_t))
#endif
#endif

/* Explicitly override malloc/free etc when using tcmalloc. */
#if defined(USE_TCMALLOC)
#define rdb_malloc(size) tc_malloc(size)
#define rdb_calloc(count,size) tc_calloc(count,size)
#define rdb_realloc(ptr,size) tc_realloc(ptr,size)
#define rdb_free(ptr) tc_free(ptr)
#elif defined(USE_JEMALLOC)
#define rdb_malloc(size) je_malloc(size)
#define rdb_calloc(count,size) je_calloc(count,size)
#define rdb_realloc(ptr,size) je_realloc(ptr,size)
#define rdb_free(ptr) je_free(ptr)
#else
#define rdb_malloc(size) malloc(size)
#define rdb_calloc(count, size) calloc(count, size)
#define rdb_realloc(ptr, size) realloc(ptr, size)
#define rdb_free(ptr) free(ptr)
#endif

#if defined(__ATOMIC_RELAXED)
#define update_zmalloc_stat_add(__n) __atomic_add_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
#define update_zmalloc_stat_sub(__n) __atomic_sub_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
#elif defined(HAVE_ATOMIC)
#define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n))
#define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n))
#else
#define update_zmalloc_stat_add(__n) do { \
    pthread_mutex_lock(&used_memory_mutex); \
    used_memory += (__n); \
    pthread_mutex_unlock(&used_memory_mutex); \
} while(0)

#define update_zmalloc_stat_sub(__n) do { \
    pthread_mutex_lock(&used_memory_mutex); \
    used_memory -= (__n); \
    pthread_mutex_unlock(&used_memory_mutex); \
} while(0)

#endif

#define update_zmalloc_stat_alloc(__n) do { \
    size_t _n = (__n); \
    if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
    if (zmalloc_thread_safe) { \
        update_zmalloc_stat_add(_n); \
    } else { \
        used_memory += _n; \
    } \
} while(0)

#define update_zmalloc_stat_free(__n) do { \
    size_t _n = (__n); \
    if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
    if (zmalloc_thread_safe) { \
        update_zmalloc_stat_sub(_n); \
    } else { \
        used_memory -= _n; \
    } \
} while(0)

static size_t used_memory = 0;
static int zmalloc_thread_safe = 0;
pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;

static void zmalloc_default_oom ( size_t size )
{
    fprintf (stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
             size);
    fflush (stderr);
    abort ();
}

static void (*zmalloc_oom_handler )( size_t ) = zmalloc_default_oom;

void *zmalloc ( size_t size )
{
    void *ptr = rdb_malloc (size + PREFIX_SIZE);

    if ( ! ptr ) zmalloc_oom_handler (size);
#ifdef HAVE_MALLOC_SIZE
    update_zmalloc_stat_alloc (zmalloc_size (ptr));
    return ptr;
#else
    *( ( size_t* ) ptr ) = size;
    update_zmalloc_stat_alloc (size + PREFIX_SIZE);
    return ( char* ) ptr + PREFIX_SIZE;
#endif
}

void *zcalloc ( size_t size )
{
    void *ptr = rdb_calloc (1, size + PREFIX_SIZE);

    if ( ! ptr ) zmalloc_oom_handler (size);
#ifdef HAVE_MALLOC_SIZE
    update_zmalloc_stat_alloc (zmalloc_size (ptr));
    return ptr;
#else
    *( ( size_t* ) ptr ) = size;
    update_zmalloc_stat_alloc (size + PREFIX_SIZE);
    return ( char* ) ptr + PREFIX_SIZE;
#endif
}

void *zrealloc ( void *ptr, size_t size )
{
#ifndef HAVE_MALLOC_SIZE
    void *realptr;
#endif
    size_t oldsize;
    void *newptr;

    if ( ptr == NULL ) return zmalloc (size);
#ifdef HAVE_MALLOC_SIZE
    oldsize = zmalloc_size (ptr);
    newptr = rdb_realloc (ptr, size);
    if ( ! newptr ) zmalloc_oom_handler (size);

    update_zmalloc_stat_free (oldsize);
    update_zmalloc_stat_alloc (zmalloc_size (newptr));
    return newptr;
#else
    realptr = ( char* ) ptr - PREFIX_SIZE;
    oldsize = * ( ( size_t* ) realptr );
    newptr = rdb_realloc (realptr, size + PREFIX_SIZE);
    if ( ! newptr ) zmalloc_oom_handler (size);

    *( ( size_t* ) newptr ) = size;
    update_zmalloc_stat_free (oldsize);
    update_zmalloc_stat_alloc (size);
    return ( char* ) newptr + PREFIX_SIZE;
#endif
}

/* Provide zmalloc_size() for systems where this function is not provided by
 * malloc itself, given that in that case we store a header with this
 * information as the first bytes of every allocation. */
#ifndef HAVE_MALLOC_SIZE

size_t zmalloc_size ( void *ptr )
{
    void *realptr = ( char* ) ptr - PREFIX_SIZE;
    size_t size = * ( ( size_t* ) realptr );
    /* Assume at least that all the allocations are padded at sizeof(long) by
     * the underlying allocator. */
    if ( size & ( sizeof (long ) - 1 ) ) size += sizeof (long )-( size & ( sizeof (long ) - 1 ) );
    return size + PREFIX_SIZE;
}
#endif

void zfree ( void *ptr )
{
#ifndef HAVE_MALLOC_SIZE
    void *realptr;
    size_t oldsize;
#endif

    if ( ptr == NULL ) return;
#ifdef HAVE_MALLOC_SIZE
    update_zmalloc_stat_free (zmalloc_size (ptr));
    rdb_free (ptr);
#else
    realptr = ( char* ) ptr - PREFIX_SIZE;
    oldsize = * ( ( size_t* ) realptr );
    update_zmalloc_stat_free (oldsize + PREFIX_SIZE);
    rdb_free (realptr);
#endif
}

char *zstrdup ( const char *s )
{
    size_t l = strlen (s) + 1;
    char *p = zmalloc (l);

    memcpy (p, s, l);
    return p;
}

size_t zmalloc_used_memory ( void )
{
    size_t um;

    if ( zmalloc_thread_safe )
    {
#if defined(__ATOMIC_RELAXED) || defined(HAVE_ATOMIC)
        um = update_zmalloc_stat_add (0);
#else
        pthread_mutex_lock (&used_memory_mutex);
        um = used_memory;
        pthread_mutex_unlock (&used_memory_mutex);
#endif
    }
    else
    {
        um = used_memory;
    }

    return um;
}

void zmalloc_enable_thread_safeness ( void )
{
    zmalloc_thread_safe = 1;
}

void zmalloc_set_oom_handler ( void (*oom_handler )( size_t ) )
{
    zmalloc_oom_handler = oom_handler;
}

/* Get the RSS information in an OS-specific way.
 *
 * WARNING: the function zmalloc_get_rss() is not designed to be fast
 * and may not be called in the busy loops where Redis tries to release
 * memory expiring or swapping out objects.
 *
 * For this kind of "fast RSS reporting" usages use instead the
 * function RedisEstimateRSS() that is a much faster (and less precise)
 * version of the function. */

#if defined(HAVE_PROC_STAT)
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

size_t zmalloc_get_rss ( void )
{
    int page = sysconf (_SC_PAGESIZE);
    size_t rss;
    char buf[4096];
    char filename[256];
    int fd, count;
    char *p, *x;

    snprintf (filename, 256, "/proc/%d/stat", getpid ());
    if ( ( fd = open (filename, O_RDONLY) ) == - 1 ) return 0;
    if ( read (fd, buf, 4096) <= 0 )
    {
        close (fd);
        return 0;
    }
    close (fd);

    p = buf;
    count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
    while ( p && count -- )
    {
        p = strchr (p, ' ');
        if ( p ) p ++;
    }
    if ( ! p ) return 0;
    x = strchr (p, ' ');
    if ( ! x ) return 0;
    *x = '\0';

    rss = strtoll (p, NULL, 10);
    rss *= page;
    return rss;
}
#elif defined(HAVE_TASKINFO)
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <mach/task.h>
#include <mach/mach_init.h>

size_t zmalloc_get_rss ( void )
{
    task_t task = MACH_PORT_NULL;
    struct task_basic_info t_info;
    mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;

    if ( task_for_pid (current_task (), getpid (), &task) != KERN_SUCCESS )
        return 0;
    task_info (task, TASK_BASIC_INFO, ( task_info_t ) & t_info, &t_info_count);

    return t_info.resident_size;
}
#else

size_t zmalloc_get_rss ( void )
{
    /* If we can't get the RSS in an OS-specific way for this system just
     * return the memory usage we estimated in zmalloc()..
     *
     * Fragmentation will appear to be always 1 (no fragmentation)
     * of course... */
    return zmalloc_used_memory ();
}
#endif

/* Fragmentation = RSS / allocated-bytes */
float zmalloc_get_fragmentation_ratio ( size_t rss )
{
    return ( float ) rss / zmalloc_used_memory ();
}

/* Get the sum of the specified field (converted form kb to bytes) in
 * /proc/self/smaps. The field must be specified with trailing ":" as it
 * apperas in the smaps output.
 *
 * Example: zmalloc_get_smap_bytes_by_field("Rss:");
 */
#if defined(HAVE_PROC_SMAPS)

size_t zmalloc_get_smap_bytes_by_field ( char *field )
{
    char line[1024];
    size_t bytes = 0;
    FILE *fp = fopen ("/proc/self/smaps", "r");
    int flen = strlen (field);

    if ( ! fp ) return 0;
    while ( fgets (line, sizeof (line ), fp) != NULL )
    {
        if ( strncmp (line, field, flen) == 0 )
        {
            char *p = strchr (line, 'k');
            if ( p )
            {
                *p = '\0';
                bytes += strtol (line + flen, NULL, 10) * 1024;
            }
        }
    }
    fclose (fp);
    return bytes;
}
#else

size_t zmalloc_get_smap_bytes_by_field ( char *field )
{
    ( ( void ) field );
    return 0;
}
#endif

size_t zmalloc_get_private_dirty ( void )
{
    return zmalloc_get_smap_bytes_by_field ("Private_Dirty:");
}

/* Returns the size of physical memory (RAM) in bytes.
 * It looks ugly, but this is the cleanest way to achive cross platform results.
 * Cleaned up from:
 *
 * http://nadeausoftware.com/articles/2012/09/c_c_tip_how_get_physical_memory_size_system
 *
 * Note that this function:
 * 1) Was released under the following CC attribution license:
 *    http://creativecommons.org/licenses/by/3.0/deed.en_US.
 * 2) Was originally implemented by David Robert Nadeau.
 * 3) Was modified for Redis by Matt Stancliff.
 * 4) This note exists in order to comply with the original license.
 */
size_t zmalloc_get_memory_size ( void )
{
#if defined(__unix__) || defined(__unix) || defined(unix) || \
    (defined(__APPLE__) && defined(__MACH__))
#if defined(CTL_HW) && (defined(HW_MEMSIZE) || defined(HW_PHYSMEM64))
    int mib[2];
    mib[0] = CTL_HW;
#if defined(HW_MEMSIZE)
    mib[1] = HW_MEMSIZE; /* OSX. --------------------- */
#elif defined(HW_PHYSMEM64)
    mib[1] = HW_PHYSMEM64; /* NetBSD, OpenBSD. --------- */
#endif
    int64_t size = 0; /* 64-bit */
    size_t len = sizeof (size );
    if ( sysctl (mib, 2, &size, &len, NULL, 0) == 0 )
        return ( size_t ) size;
    return 0L; /* Failed? */

#elif defined(_SC_PHYS_PAGES) && defined(_SC_PAGESIZE)
    /* FreeBSD, Linux, OpenBSD, and Solaris. -------------------- */
    return ( size_t ) sysconf (_SC_PHYS_PAGES) * ( size_t ) sysconf (_SC_PAGESIZE);

#elif defined(CTL_HW) && (defined(HW_PHYSMEM) || defined(HW_REALMEM))
    /* DragonFly BSD, FreeBSD, NetBSD, OpenBSD, and OSX. -------- */
    int mib[2];
    mib[0] = CTL_HW;
#if defined(HW_REALMEM)
    mib[1] = HW_REALMEM; /* FreeBSD. ----------------- */
#elif defined(HW_PYSMEM)
    mib[1] = HW_PHYSMEM; /* Others. ------------------ */
#endif
    unsigned int size = 0; /* 32-bit */
    size_t len = sizeof (size );
    if ( sysctl (mib, 2, &size, &len, NULL, 0) == 0 )
        return ( size_t ) size;
    return 0L; /* Failed? */
#endif /* sysctl and sysconf variants */

#else
    return 0L; /* Unknown OS. */
#endif
}


